CN102757636A - Inflaming retarding thermoplastic polyurethane elastic body - Google Patents

Abstract

The invention discloses an inflaming retarding thermoplastic polyurethane elastic body which comprises the following components by weight percentage of: 60-80% of polyester thermoplastic polyurethane, 10-30% of halogen-free fire retardant, 1-10% of inflaming retarding synergist, 1-10% of chain extender, 0.1-2% of antioxidant and less than 5% of non-inflaming-retarding additive. According to the inflaming retarding thermoplastic polyurethane elastic body disclosed by the invention, the good inflaming retarding performance can be achieved and relatively good mechanical performances of previous high tensile strength, cracking elongation at break and the like of a TPU (Thermoplastic Polyurethane) raw material; the inflaming retarding thermoplastic polyurethane elastic body has the advantages of good wear resistance, tearing resistance, hydrolysis resistance and anti-ageing performance; and the inflaming retarding thermoplastic polyurethane elastic body does not contain halogens and heavy metal and particularly does not contain lead, cadmium, mercury, hexavalent chromium heavy metal, as well as poly-brominated diphenyl ether and poly-brominated biphenyls, so that the European Union RoH2.0 instruction requirements are met.

Description

Flame retardant thermoplastic polyurethane elastomer

Technical field

The invention belongs to polymeric material field, be specifically related to a kind of flame retardant thermoplastic polyurethane elastomer.

Background technology

TPU is that thermoplastic polyurethane is a kind of novel organic polymer synthetic materials; Has good extension recovery; Cold-resistant, oil resistant, folding are curved, anti-ozone ageing etc., especially have excellent abrasive, are widely used in the industrial circles such as automobile, electric wire, medicine, shoe industry.But the flame retardant resistance of thermoplastic polyurethane is relatively poor, in case burning, flame is very violent and with strong black smoke, there is the risk that enlarges the fire intensity of a fire while with serious molten drop phenomenon.In addition, thermoplastic polyurethane hydrolytic resistance, ageing resistance are relatively poor.

One of method of improving the thermoplastic polyurethane flame retardant resistance is in thermoplastic polyurethane, to add fire retardant, and fire retardant generally is divided into halogen containing flame-retardant and halogen-free flame retardants.The smog that produces during the halogen containing flame-retardant burning contains deleterious corrosive hydrogen halides gas, is detrimental to health and environment protection, does not also meet Europe RoHS 2.0 " using the instruction of some objectionable constituent about restriction in electronic and electrical equipment " command request.Therefore, generally select for use halogen-free flame retardants to improve the flame retardant resistance of thermoplastic polyurethane.But after adding fire retardant in the thermoplastic polyurethane of prior art, when improving flame retardant resistance, often obviously reduced mechanical property such as tensile strength, elongation at break etc., over-all properties is relatively poor.

Summary of the invention

Technical problem to be solved by this invention is, to the deficiency of prior art, a kind of good flame resistance is provided, and good mechanical property simultaneously, meets the flame retardant thermoplastic polyurethane elastomer of Europe RoHS 2.0 command requests at anti-aging, Halogen.

The present invention solves the problems of the technologies described above the technical scheme that is adopted: flame retardant thermoplastic polyurethane elastomer, and its weight percent is formed and is comprised:

Polyester type thermoplastic polyurethane 60 ~ 80%,

Halogen-free flame retardants 10 ~ 30%,

Fire retarding synergist 1 ~ 10%,

Chainextender 1 ~ 10%,

Oxidation inhibitor 0.1 ~ 2%,

Non-flame-retardant additive is below 5%.

Preferably, described halogen-free flame retardants is the mixture of nitrogen system bittern-free fire retardant and phosphorus series non-halogen fire retardant, and the weight percentage of the nitrogen system bittern-free fire retardant described in this mixture is 60 ~ 75%.

Preferably, described nitrogen system bittern-free fire retardant is trimeric cyanamide, Dyhard RU 100 or melamine cyanurate.

Preferably; Described melamine cyanurate adopts organo-silicon coupling agent to carry out surface activation process, and described organo-silicon coupling agent is at least a in γ-An Bingjisanyiyangjiguiwan, N-β (aminoethyl)-γ-An Bingjisanjiayangjiguiwan, γ-glycidyl ether oxygen propyl, Trimethoxy silane, vinyl three ('beta '-methoxy oxyethyl group) silane.

Preferably, described phosphorus series non-halogen fire retardant is phosphoric acid salt, phosphinate or hypophosphite.

Preferably, described hypophosphite has suc as formula the structural formula shown in the I:

Formula I

Wherein R1 and R2 represent C1 ~ C6 alkyl; M represents calcium, aluminium, magnesium or zinc; N represents 2 or 3.

Preferably, described fire retarding synergist is at least a in zinc borate, the rare earth.

Preferably; Described chainextender is selected from least a in polybutylene terephthalate, polyethylene terephthalate, polyethylene terephthalate-1,4 cyclohexane dimethanol ester, hydroxyl or amino multi-functional alcohols or the aminated compounds.

Preferably; Described oxidation inhibitor is selected from β-(3; The 5-di-tert-butyl-hydroxy phenyl) the positive octadecanol ester of propionic acid, four [methyl-β-(3; The 5-di-tert-butyl-hydroxy phenyl) propionic ester] pentaerythritol ester, three ［ 2.4-di-tert-butyl-phenyl ］ phosphorous acid ester, N, N'-is two-at least a in (3-(3, the 5-di-tert-butyl-hydroxy phenyl) propionyl group) hexanediamine.

Preferably, described non-flame-retardant additive comprises at least a in tinting material, photostabilizer, the inert packing.

At least a in fire retarding synergist preferred boric acid zinc, the rare earth, the preferred lanthanide rare of its middle-weight rare earths, lanthanide rare increases thermostability, and the zinc borate increase becomes charcoal property.

In polyurethane material, there are responsive to hydrolysis in a large number group such as ester group, carbamate and urea groups etc., can react with water, generate carboxylic acid and alcohol, and carboxylic acid further promotes the hydrolysis of ester group as catalyzer, reaction mechanism is following:

RCOOR '+H₂O → RCOOH+R ' OH ester

RNHCONHR '+H₂O → RNHCOOH+R ' NH₂Urea

RNHCOOR '+H₂O → RNHCOOH+R ' OH carbamate

Chainextender recovers its original molecular weight and limiting viscosity through the functional group and the end group generation chemical reaction of degradation polymer, reduces melting index, has efficiently end-blocking and chain and repairs ability, thereby improve the hydrolytic resistance of material.

The present invention is through adding halogen-free flame retardants, fire retarding synergist, chainextender, oxidation inhibitor and non-flame-retardant additive in the polyester type thermoplastic polyurethane; When reaching excellent flame-retardant performance; Guaranteed mechanical property preferably such as original high tensile of TPU material and elongation at break; And have good wear resistance, tear strength, hydrolytic resistance and a resistance to deterioration; And the present invention is not halogen-containing and heavy metal, and especially not leaded, cadmium, mercury, sexavalent chrome heavy metal and gather dibromodiphenyl ether and gather bromo biphenyl satisfy the RoHS2.0 of European Union command request.

It is the V-0 burning grade of 3.0mm that the flame retardant resistance of flame retardant thermoplastic polyurethane elastomer of the present invention can reach according to the UL94 measured thickness, and oxygen index reaches more than 28; Shore hardness 87A is above, tensile strength 25MPa above, elongation at break is more than 450%; Under 136 ℃, the aging condition of 168h, the tensile strength retention rate is more than 85%, and reserved elongation at break is more than 90%.

Embodiment

Below in conjunction with embodiment the present invention is described in further detail.

The production process of testing the sample of the required embodiment of the invention and Comparative Examples is: at first; Adopt twin screw extruder to carry out melt kneading raw material; Then the fusion output from the forcing machine die head is cooled off through cooling tank, be made into the pellet of flame retardant thermoplastic polyurethane elastomer at last.Use injection moulding machine that the pellet of prepared flame retardant thermoplastic polyurethane elastomer is carried out injection moulding, and at room temperature sufficient stabilization finally obtain sample to be tested, carries out each item performance test.

The weight percent proportioning of embodiment and Comparative Examples is the table one of face as follows, and its performance and comparing result be the table two of face as follows.

The weight percent proportioning of table one: embodiment and Comparative Examples

The performance of table two: embodiment and Comparative Examples and comparing result

When preparing flame retardant thermoplastic polyurethane elastomer of the present invention, at first under 100 ℃ with dry about 2 ~ 5 hours of polyester type thermoplastic polyurethane; Can adopt any method well known by persons skilled in the art that polyester type thermoplastic polyurethane, halogen-free flame retardants, fire retarding synergist, chainextender, oxidation inhibitor and other non-flame-retardant additive (if interpolation) is together mixing then; The mixing granulation temperature of fusion is 150 ℃ ~ 215 ℃; Preferred 160 ℃ ~ 190 ℃, more preferably 170 ℃ ~ 180 ℃.Usually; The fusing point of polyester type thermoplastic polyurethane is 150 to 250 ℃; Employed concrete temperature of fusion depends on the fusing point of the polyester type thermoplastic polyurethane that uses in the flame retardant thermoplastic polyurethane elastomer of the present invention, as those skilled in the art fully understand.Flame retardant thermoplastic polyurethane elastomer of the present invention can use equipment such as mill, Banbury mixer, single screw extrusion machine, twin screw extruder to prepare, but considers melt kneading performance and production efficiency, and most preferred equipment is twin screw extruder.

Claims (10)

1. flame retardant thermoplastic polyurethane elastomer is characterized in that, its weight percent is formed and comprised:

Polyester type thermoplastic polyurethane 60 ~ 80%,

Halogen-free flame retardants 10 ~ 30%,

Fire retarding synergist 1 ~ 10%,

Chainextender 1 ~ 10%,

Oxidation inhibitor 0.1 ~ 2%,

Non-flame-retardant additive is below 5%.

2. flame retardant thermoplastic polyurethane elastomer according to claim 1; It is characterized in that: described halogen-free flame retardants is the mixture of nitrogen system bittern-free fire retardant and phosphorus series non-halogen fire retardant, and the weight percentage of the nitrogen system bittern-free fire retardant described in this mixture is 60 ~ 75%.

3. flame retardant thermoplastic polyurethane elastomer according to claim 2 is characterized in that: described nitrogen system bittern-free fire retardant is trimeric cyanamide, Dyhard RU 100 or melamine cyanurate.

4. flame retardant thermoplastic polyurethane elastomer according to claim 3; It is characterized in that: described melamine cyanurate adopts organo-silicon coupling agent to carry out surface activation process, and described organo-silicon coupling agent is at least a in γ-An Bingjisanyiyangjiguiwan, N-β (aminoethyl)-γ-An Bingjisanjiayangjiguiwan, γ-glycidyl ether oxygen propyl, Trimethoxy silane, vinyl three ('beta '-methoxy oxyethyl group) silane.

5. flame retardant thermoplastic polyurethane elastomer according to claim 2 is characterized in that: described phosphorus series non-halogen fire retardant is phosphoric acid salt, phosphinate or hypophosphite.

6. flame retardant thermoplastic polyurethane elastomer according to claim 5 is characterized in that: described hypophosphite has suc as formula the structural formula shown in the I:

Formula I

Wherein R1 and R2 represent C1 ~ C6 alkyl; M represents calcium, aluminium, magnesium or zinc; N represents 2 or 3.

7. flame retardant thermoplastic polyurethane elastomer according to claim 1 is characterized in that: described fire retarding synergist is at least a in zinc borate, the rare earth.

8. flame retardant thermoplastic polyurethane elastomer according to claim 1; It is characterized in that: described chainextender is selected from least a in polybutylene terephthalate, polyethylene terephthalate, polyethylene terephthalate-1,4 cyclohexane dimethanol ester, hydroxyl or amino multi-functional alcohols or the aminated compounds.

9. flame retardant thermoplastic polyurethane elastomer according to claim 1; It is characterized in that: described oxidation inhibitor is selected from β-(3; The 5-di-tert-butyl-hydroxy phenyl) the positive octadecanol ester of propionic acid, four [methyl-β-(3; The 5-di-tert-butyl-hydroxy phenyl) propionic ester] pentaerythritol ester, three ［ 2.4-di-tert-butyl-phenyl ］ phosphorous acid ester, N, N'-is two-at least a in (3-(3, the 5-di-tert-butyl-hydroxy phenyl) propionyl group) hexanediamine.

10. flame retardant thermoplastic polyurethane elastomer according to claim 1 is characterized in that: described non-flame-retardant additive comprises at least a in tinting material, photostabilizer, the inert packing.